1. Field of the Invention
This invention pertains generally to the field of aviation and the generation of approach and departure procedure data associated with arrival and departure paths into and out of any airport for use in avionics equipment installed in an aircraft.
2. Description of the Related Art
An instrument approach procedure is a type of air navigation that allows a pilot to land an aircraft in reduced visibility commonly referred to as instrument meteorological conditions. Generally, an approach procedure permits a pilot to descend to a decision altitude or minimum descent altitude where a pilot is required to see the runway environment to continue descending towards the runway for landing or discontinue the approach by executing a missed approach. Instrument approach procedures have evolved. Initially, approach procedures have been developed using ground-based navigation facilities. With the advent of a global navigation satellite system (“GNSS”) (or satellite navigation system), approach procedures are no longer restricted to navigation fixes or waypoints defined by ground-based facilities. Instead, waypoints can be established using the latitude/longitude coordinate system. With the advent of the GNSS, approach procedures have been created by aviation-governing authorities using waypoints as part of area navigation (“RNAV”).
In addition to instrument approach procedure, a departure procedure is a type of air navigation that allows a pilot to take-off an aircraft following a prescribed procedure. A published departure procedure provides flight procedures for an aircraft to follow to ensure either an obstacle-free departure path or to permit the aircraft to follow a defined route required by ATC for air traffic flow management.
The design of approach and departure procedures includes the construction of an obstacle clearance surface (“OCS”). An OCS is constructed to provide the pilot assurance that the approach and departure procedure is free from objects such as obstacles and terrain. With the use of design criteria, an OCS may be constructed and examined for objects penetrating the surface of the OCS. If an object penetrates that OCS, then adjustments will have to be made to the OCS. In an area of mountainous terrain, this could significantly impact the decision altitude or minimum descent altitude to where a pilot may descend the aircraft; also, it could significantly impact the ability for a pilot to take-off from a runway in poor visibility conditions. Current approach and departure procedure design criteria do not provide for remedies which allow the surface of an OCS to be penetrated.